Urinary incontinence is a disorder that generally affects people of all ages. The inability to control urination can impact a patient both physiologically and psychologically. Urinary incontinence can interfere with a patient's daily activity and impair quality of life. Stress urinary incontinence is one type of urinary incontinence. Actions including straining, coughing, and heavy lifting can cause those with stress urinary incontinence to void urine involuntarily.
Various physiological conditions cause urinary incontinence in women. Stress urinary incontinence generally is caused by two conditions that occur independently or in combination, intrinsic sphincter deficiency and hypermobility. Intrinsic sphincter deficiency (ISD) is a condition where the urethral sphincter fails to coapt properly. When functioning properly, the urethral sphincter muscles relax to enable the patient to void, and the sphincter muscles are otherwise constricted to retain urine. ISD may cause urine to leak out of the urethra during stressful actions. Hypermobility is a condition where the pelvic floor is weakened or damaged causing the bladder neck and proximal urethra to rotate and descend in response to increases in intraabdominal pressure. When intraabdominal pressure increases (due, for example, to strain resulting from coughing), the hypermobility condition may cause urine leakage. Some women suffer from a combination of ISD and hypermobility.
The methods for treating stress urinary incontinence include placing a sling to either compress the urethral sphincter or placing a sling to support, elevate or provide a “back stop” to the bladder neck and proximal urethra. Providing support to the bladder neck and proximal urethra maintains the urethra in the normal anatomical position and elevation places the urethra above the normal anatomical position. The “back stop” prevents descent according to the hammock theory such that the back stop prevents the bladder neck from descending upon application of strain.
Generally, slings are employed to support anatomical structures. Slings may be made from one or more materials derived from non-synthetic material(s), for example, mammalian tissue(s), synthetic material(s), or from a combination of non-synthetic material(s) and synthetic material(s).
The presence of non-synthetic material(s) can prevent erosion and irritation, caused by the use of synthetic materials alone. It has been observed that the interaction between the synthetic material of a sling and the body may cause erosion into the body, e.g., the urethra or vagina. The incorporation of non-synthetic material(s) into the sling prevents this erosion, thereby increasing patient comfort.
After implantation in a patient, slings made from mammalian tissues typically require a six to twelve month period to be absorbed by the patient's body, after which the implanted mammalian tissue is not recognizable from the patient's surrounding tissue. Mammalian tissue slings include tissue harvested from the patient or a donor. In some instances, the mammalian tissue may be human cadaveric tissue.